Improvement in watch-escapements



PATENT CEEICE.

ABEL COOMBS, OF BURLINGAME, KANSAS.

IMPROVEMENT IN WATCH-ESCAPEMENTS.

Specification forming part of Letters Patent No. 121,337, dated November 28,1871.

To all ywhom it 'may concern:

Be it known that l, ABEL COOMBS, of Burlingame, in the county of Osage and State of Kansas, have invented a new and useful Improvement in Watch-Escapements, and l do hereby declare the following to be a clear and exact description ofthe nature thereof sufficient to enable others skilled inthe art to which my invention appertains to fully understand and use the same, reference being had to the accompanying drawing making part of this specification.

The invention consists in improvements which will be flrst fully described and then clearly pointed out in the claim.

Figure l is a face view of my improved watch. Fig. 2 is a view with the face removed. Fig. 3 is a section taken about midway between the back and front plate, and looking toward the latter. Fig. ais atransverse section of the watch. Fig. 5 is a side elevation of the lever 5 Fig. 6, a plan of the lever.

a represents the lever, which is pivoted at b, and has one short pallet, d, near said pivot, and another longer one, e, at a much greater distance on the opposite side of said pivot and toward the roller-table j', of which j" is the pin. This lever, instead of being forked to receive the roller-pin between said forks, which, in the old way, act alternately on said pin, terminates in a bent arm, g, passing the roller-pin on one side, and has a spring, h, on the side opposite the escapement-wheel t', extending past said pin on the other side, said spring being supported near its end by a pin, 7c, rising up from a projection, Z, at the end of said lever. By this arrangement the lever only acts on the roller-pin during its vibration in one direction-that is, when the tappets of the scape-wheel are acting on pallet c and forcing the arm g outward, but it will be seen that this pallet is twice as far from the pivot as it could be if arranged in the common way, and consequently the wheel has twice the leverage to act on the roller-pin and throw the balance, thereby making only one escapement to two as heretofore, and avoiding one-half the stops of the train. The office of the short pallet d is merely to throw the lever back against, as the tappets of the escape-wheel pass it without stopping.

The train only stops as the balance swings one way, while in the common arrangement it stops every time the balance swings either way. The less stopping and starting a watch has to perform the better for the whole machinery; and it is less likely to cease running, as it has only half the stoppings to overcome, and as the cessations occur from failing to start after any of these stops. The spring lo strikes against the collar-pin in the return-stroke of the lever and arrests the blow of the pallet on the scape-wheel tappet which would otherwise occur.

By this4 arrangement the -roller-table is constructed with the banking77 notch on one side of the roller-pin, and, therefore, the watch can only overbank77 on one side ofthe same 5 whereas, in the common way, they may overbank on either side of the pin, owing to the notch being in iront of the roller-pin.

As, by this plan, the lever moves twice as far at one beat, it is more likely to overcome any obstruction in the train. The lever is crnved in its side between the pallets, as shown at m, and it is also slotted at a so that the escapewheel is set closer to it and economizes space. l also gain power by getting a wider sweep of the lever, in consequence of which I can increase the size of the roller and arrange the roller-pin further from the roller-axes, thus gaining leverage on the balance. In consequence of this enlargement of the roller the ba-nking-notch may be made much deeper, so that the banking-pin will reach into the roller so far that it cannot overbank, which all other watches with detached levers frequently do and stop immediately, or throw-off77 and catch the banking-pin on the edge of the roller in the line ofthe balance-staff, which also stops the watch.

My banking-pin g', striking into the roller on one side of the roller-pin, never gets on the other side, as the lever always stops on one side of the balance-staff, while a common lever stops on both sides, and, in passing the line, dips into the roller in front of the pin but slightly, whereby, the sweep being narrow, the roller small, and the banking-notch necessarily shallow, the watch is frequently stopped.

Having thus described all that is necessary t0 a full understanding of my invention, what I 2. The arrangement of the lever, roller, rolleresteem to be new7 and desire t0 protect by Letpin, banking-pin, and banking-notch, for operaters Patent, is tion substantially as specified.

l. The lever having the pallets d e arranged ABEL GOOMBS.

relatively to the pivot and the escape-Wtieei7 and arranged With the roller and relier-pin on the Witnesses:

balancestafffor increasing' the leverage and stop- J EssE BROCKWAY,

ping the train only once for the beats of the bal- PAUL JORDAN. (36) ance, all substantially as specified. 

